Ditching attachment for mobile posthole diggers



1 193 M. w. CLARK EI'AL 2,5854

DITCHING ATTACHMENT FOR MOBILE POSTHOLE DIGGERS Filed Jan. 21, 1948 3 Sheets-Sheet l June 26, 1951 M, w. CLARK ETAL DITCHING ATTACHMENT FOR MOBILE POSTHOLE DIGGERS Filed Jan. 21, 1948 I5 Sheets-Sheet 2 Ivy/wig Maria/2 W JW/r flew/am 1/17 June 26, 95 M. w. CLARK EI'AL DITCHING ATTACHMENT FOR MOBILE POSTHOLE DIGGERS Filed Jan. 21, 1948 3 Sheefs-Sheet s fi e/ m Jjfald Patented June 26.1951

OFFICE.

DITCHING ATTACHMENT FOR POSTHOLE DIGGERS Marion W. Clark and Herman J Hall, Columbia, Mo.

Application January 21, 1948,. Serial No. 3,636

Claims.

. l a Our invention. relates to apparatus for digging ditches and, more particularly, to a novelstructure for converting mobile earth-boring tools of the auger type, to ditch or trench-digging devices.

Ditchedigging devices heretofore constructed, which utilize an. auger for removing the excavated material from the ditch, operate as follows: An initial hole is dug. either by hand or by mechanical means, not. including the mechanical trench digger. The. auger and its supporting structure is then lowered. into the hole to the desiredv depth of. the trench to be. dug. The auger is then made to rotateand the trench. digger moved forwardly. by one means. or another, at a speed determined by the rate of cutting action of. the. auger. The auger is never removed from the trench until the. trench is completed. Obviously this type of trench digger is necessarily a great deal more heavy and expensive to construct than is an earthv boring. auger used for post hole diggers and the like. This is true because the post hole digger moves vertically up and down in its digging action, whereas in the former the auger is pulled behind the tractor and is hence subjected to great lateral stress in its digging action.

. from the ditch to points sufficiently remote from said ditch to prevent the excavated material from being redeposited in the trench during the ditch digging operation, but close enough for easybackfilling; of the ditch.

Other highly important objects" and advantages will become apparent fromv the following'detailed specification. appended claims, and attached drawings.

Referring to the drawings, wherein like characters indicate like: parts throughout the several views:

Fig; I is a view in side elevation, some parts broken away, showing our novel structure as utilized in digging a trench or ditch;

Fig. 2 is a fragmentary view partly in plan and partly in horizontal section taken on the line 2 -2 of Fig. 1-;

Fig. 3 is a fragmentary vertical section taken on. the line 3-3 of Fig. 2;

Fig. 4. is a fragmentary perspective view, illustrating means for mounting a follower element and means for removal of excavated material to the earth-boring mechanism; and

Fig. 5 is a perspective view of one of the mold boards used. in deflecting excavated materialv away from the trench.

Referring with greater particularity to r the drawings, the numeral I indicates, in its entirety, a conventional tractor l to the rear end. of which has been secured an earth boring auger frame comprising a laterally-spaced pair of verticallydisposed legs 2, a laterally-spaced pair of hori-.- zontal members 3, and diagonal brace elements 4. The leg elements 2 are secured attheir lower end portions to the rear ends of the horizontal members 3 by means of nut-equipped bolts or the like 5; and the brace members 4 are secured at one. end to the upper end portions of the legs 2 and at their lower ends to the forward end portions. of the horizontal members 3- A pair of skids 6 are attached to the extreme lower ends of the legs 2 and are adapted to engage the ground for the purpose of supporting the weight of the legs 2. Av rotary earthboring auger I is mounted for generally vertical reciprocal movements between the legs 2 by means of a cross head 8 slidably carried by the legs 2. Rotary movement is imparted to the auger by the power take-off. not shown, of the tractor I through connections including a drive shaft 9 andgearing not shown, but contained within the cross head 8. Vertical reciprocal movements are impartedv tothe auger 1 by means not shown, but fully de--v scribed in copending application. S. N- 674,514, filed June 5, 1946. The above-described mechanism. is that of a. conventional post. hole digger of the particular type referred to in the aboveidentified patent application. We. will next describe the mechanism which may be secured. to this or other conventional post hole diggersg'to. convert them. into efiicient. trench-digging devices. To accomplish this end, we provide a reotangular frame in comprising a pair of. laterally spaced side frame elements I- I}. one each secured fast to one of the legs 2 and connecting vertically-spaced transverse frame elements. [2.

Adapted tobe secured to the transverse frame elements 12 by means of nut-equipped bolts. [3 is a vertically downwardly-projecting follower or shield l4. provided at its upper ends with a ban.- dle member IS. The follower M has an arcuate face it which is of substantially the same arcuate contour as the circumference of the auger" "I and which lies closely adjacent the path traversed by the auger I in its vertical movement. It will be seen, particularly by reference to Fig. 2, that the follower I4 is of less width than the auger I and is positioned immediately therebehind. The upper end portion of the follower I4 is providedwith a plurality of mounting holes H which provide vertical adjustment of the follower 14 with respect to the frame-work of the digger. Alignment of any pair of the holes I1 with the mounting holes in the transverse bars l2 determines the depth to which the follower projects below the framework of the machine. It is important to note that, contrary to all previous auger type ditch digging devices, the follower M of our structure is secured to the framework of the machine in a manner to permit independent vertical movements of the auger I.

To handle the material removed from the ground in the ditch-digging operation and to position the same so it will not be redeposited in the trench either during or after the digging operation-"we provide a deflector in the nature of a V-shaped plow [Shaving a pair of rearwardly and downwardly-diverging deflecting faces IS, an arcuate inner wall 2e-which is of slightly larger'circumference than the auger "I, and a connecting relatively narrow horizontal shelf 2!. At-its rear end, the V-shaped plow is provided with vertically-extending beams 22 which are adapted to be secured by nut-equipped bolts or the" like 23 to the transverse frame elements 12. Asshown in Fig. 5, reinforcing struts or braces 2; connect the lower end of arcuate member 2i withthe forward ends of the deflecting plates 19. A' pair of laterally-spaced drawbars 25 are secured to the bottom rear portion of the V-shaped plow l8 and are provided with aligned openings 26 through which is adapted to be passed a hinge belt or the like 21. It will be seen, particularly by reference to Figs. 1 and 3, that the lower edge of the V-shaped plow I8 lies closely adjacent ground level, that is, substantially in the same plane as the bottom of the wheels of the tractor A pair of rearwardly-diverging mold boards 28 are secured to the plow l8 laterally outwardly of and adjacent to the vertically-extendingi beams. 1 "We provide further means for preventing earth from being redeposited in the trench dug by the augerin-the nature of a flat rectangular skirt which, at its forward end, is provided with a pair of laterally-spaced upstanding perforated lugs 39 adapted topivotally receive the hinge bolt 2'1. The'skirt 2 9 isreinforced by a brace member 3| extending longitudinally thereof and is of sufficient size'to'more' than cover the trench dug by the auger for a substantial distance therebehind. Rigidly secured to the skirt 29 are a pair of laterally spa cedfvertically disposed mold boards 32 which have converging forward portions 33 at their forward ends. The mold boards 32 are re info'rced at their forward and intermediate portions by transverse brace rods or the like 34.

Themethod of using our novel structure for thedigging of a trench is as follows: Prior to the attachment of the follower I4 to the framework of'the machine, as illustrated, the auger l is positioned over the point where it is desired to commence the trench. The auger l is then operated to dig a hole to the desired depth of the trench, and the auger is removed therefrom. At this point, the tractor or other device upon which the auger is mounted, is moved forward slightly in order to allow the follower i l to be lowered into the hole made by the auger and indicated in Fig. 1 by the letter a. The follower I4 is then rigidly secured to the transverse members I'Z, as above described. At this point, and whilst the auger 1 is elevated to a position above the ground, the entire digging device is moved forward to a point where the forward edges of the follower l4 come'into contact with the forward wall of the trench hole 'a. Thedevice is then stopped and the auger operated to dig a second hole b which partially overlaps the hole a. After the hole I) has been completed and the auger "I removed therefrom, the entire structure is then moved forwarduntil the leading edges of the follower l4 engage the forward wall of the hole b. This operation is repeated until a tranch of the desired length is excavated.

It is important to note that the width of the follower [4 determines the extent of the overlapping relationship between adjacent holes and likewise determines the width of the'narr'owest portion of the trench as indicated at 0. Thus, the follower I 4 passes easily from one hole to the forward wall of the hole just completed. 1

Obviously, the earth and material removed from each hole is deposited on all sides of the auger 1 above the level of the earth. That portion of the material which is deposited in a for-' ward position is obviously deflected to either side of the trenchabout to be dug, by the deflecting surface I9; That portion of the earth and material which is dropped to the sides of the auger I is deflected from the trench primarilyby means of the mold boards 28 upon forward motion of the apparatus; and that portionof the earth and material which is deposited to the rear of the auger is dropped upon the forward end of the skirt 29 approximately at the positionm. It will be here appreciated that the amount of dirt. which is elevated to a level' to be deposited upon the skirt 29 is relatively small with respect to the amount of earth and material which is deposited in' other directions (see particularly Fig. 3). However, the amount of material that is dropped upon the skirt when approximately in position a: is important in that it adds sufficient weight to the skirt 29 to hold the same snuglyagainst, the surface of the ground, at the sides of the trench. As the pile of earth'deposited, approximately in the position 'of :13, increases in size, it tends to fall off the sides of the skirt,2.9 from whence it is pushed laterally outwardly still further by virtue of the rearwardly diverging, mold board portions 32 and 33. It will be appreciated that the follower [4 acts only asa shield to prevent excavated dirt from being deposited into the excavated portion of the trench and that in this method of digging a trench there is substantially no lateral stress applied to the auger in its digging operation. For this reason, the follower may be relatively light in' weight so as to be easily handled and need not be. used to brace the lower end of the auger I' as is the case with other auger type trench diggers. our invention has been thoroughly. tested and. found to be completely satisfactory for'the ace complishment of the above objects and while we have disclosed a preferred form of our invention as required by section 4888 of the Revised. Statutes, it should be obvious that the sameis capable'of considerable modification without de-. parture from the spirit-and scope of the appended claims. a Y

What we claim is: '4 :1 r 1. In a device of the class described, ajframe;

adapted to be secured to a vehicle, a rotary earth boring auger mounted forgenerally upward and downward reciprocating movements with respect to said frame, means for imparting rotary and reciprocal movements to said auger, and a follower secured to said frame and projecting downwardly a distance substantially equal to the depth of a hole made by the auger and independent of said upward and downwardly movements of said auger, said follower having an arcuate face corresponding substantially to the circumference of said auger, said face lying closely adjacent the path traversed'by said auger during boring movements thereof.

2. The structure defined in claim 1 in which said follower is vertically adjustably secured to' said frame.

3. The structure defined in claim 1 in further combination with a V-plow secured to said frame at approximately ground level and positioned immediately ahead of said auger, and an elongated skirt horizontally pivotally secured to said frame behind said follower and extending rearwardly therefrom at ground level.

4. The structure defined in claim 1 in further combination with plow means secured to said frame at approximately ground level and posi tioned immediately ahead of said auger, a horizontally-disposed skirt having its front end pivotally secured to said frame behind said follower at approximately ground level and extending rearwardly therefrom, and rearwardly diverging mold boards secured to said frame immediately behind 6 said auger and having their rear ends projecting laterally outwardly from said skirt.

5. The structure defined in claim 1 in further combination with plow means secured to said frame at approximately ground level and positioned immediately ahead of said auger, a horizontally disposed skirt having its front end pivotally secured to said frame behind said follower at approximately ground level and extending rearwardly therefrom, rearwardly diverging mold boards secured to said frame immediately behind said auger and having their rear ends projecting laterally outwardly from said skirt, and a pair of mold boards secured to said skirt and rearwardly spaced with respect to said first-mentioned mold boards, said last-mentioned mold boards extending laterallyv outwardly beyond the first-mentioned mold boards and being provided at their forward ends with forwardly converging portions.

MARION W. CLARK. HERMAN J. HALL.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 21,225 Wells Aug. 1'7, 1858 322,656 Titus et al July 21, 1885 2,360,334 Engel et al Oct. 17, 1944 2,381,689 Roehr Aug. 7, 1945 2,417,313 MacK nn n ne Marwe? 

